The invention concerns the packaging of products such as creams manufactured for the cosmetic, pharmaceutical, fragrance and even food industries. In particular, the invention targets the packaging of small quantities, 15 ml at most, which are likely to be used as demonstration or other types of supples. Nevertheless, the invention may be adapted for packaging greater quantities, as well as for powdered or fairly viscous fluid products.
In the type of packaging addressed in the invention, the determining factors are rapid and low cost manufacturing the packaging, and satisfactory, if not perfectly airtight, insulation of the contents in relation to the ambient atmosphere. These goals are met in a simple fashion using the packaging means of the invention, which has as its object a vessel including a container, a top and a flexible hinge connecting the container and the top, wherein the container, the top and the flexible hinge are made of the same material.
This vessel may be made using quick, simple and economical processes as explained below. Perfect airtightness may be guaranteed in certain modes of implementation. Numerous forms of the hinge, made of the same material as the container and the top, are compatible with the invention, such as a flexible tab, for example.
Preferably, the flexible hinge is a spring-action hinge. Through this action, the hinge moves the top into either the open or closed position from an intermediary unstable equilibrium position. Such a flexible hinge, which is advantageous because it does not include any large protruding parts, makes it possible to use traditional filling machines and is described in relation to a dispensing closure in French patent B1-2 498 240, which is herein incorporated by reference. Such a dispensing closure, which is widely used for food and cosmetic products, especially for shampoo, is commonly of a roughly cylindrical geometry; it is screwed by its lower open part onto the neck of a bottle and its upper part is closed by a top connected to it by a hinge. The dispensing closure also includes a transverse wall having a through opening permits a controlled flow of the contained product under the effect, for example, of pressure exerted on the sides of the bottle.
The vessel of the invention advantageously includes means for locking the closed position of the top, these means may consist of a part of the container which forms a relief with respect to the top, allowing the container to fit into a concavity of the top, which of course has a position and shape corresponding to those of the relief. The effect produced is a snap fit of the top onto the container.
Other relief forms and/or concavity forms, such as ring-shaped forms, may also be used at the edge of the container and/or the top in order to guarantee the airtightness of the vessel of the invention, while also participating, if necessary, in locking the top in closed position as described above.
The preferred material for constituting the vessel of the invention is an injectable plastic material. The latter includes a material molded by reaction injection molding (R.I.M.); this technique involves injection of liquid polycondensation reagents into a mold. The injectable plastic material may also include a thermoplastic material molded using traditional injection. Preferably, this material consists of a non-styrene polyolefin or of a mixture of such polyolefins, selected from among a polypropylene, a propylene copolymer or a polyethelene.
According to a feature of the invention, the outer surface of the vessel, that is, its visible surface when the top is in closed position, defines a concavity at the joint between the container and the top. A user can initiate the opening of the top by pressing the edges of the concavity. In this variation, one of said edges necessarily belongs to the container and the other belongs to the top, such that the container and the top may be separated from one another.
In an especially interesting mode of implementation, the top has a traversing hole. It should be noted that in the absence of this characteristic, filling the vessel requires the prior opening of the top. When the top is in an open position, it is more difficult to position an optional printed motif on the periphery of the vessel using an offset-type technique; moreover, when the vessels are passed into vibrating feeders, if the tops are open some of the vessels may push each other out of the feeders, which does not occur when the top is in closed position, thereby making possible a more consistent and homogeneous dispensing of vessels in the feeders.
The vessels are filled via the traversing hole in the top, then the traversing hole is sealed by a casting corresponding in shape to that of the traversing hole. This casting may be, but is not necessarily, constituted in the same manner as the other parts of the vessel. This sealing may be done by pressing the casting onto the edges of the traversing hole or by fitting the casting onto these edges and applying an adhesive film covering the upper surface of the casting and the top, or the like.
Another object of the invention is an injection manufacturing process of the vessel described above. This process is simple, quick and economical. It also allows vessels of different capacities to be manufactured by modifying only one of the two half-molds, or even by removing or adding removable parts to this half-mold.
Other objects of the invention consist in using the vessel described above to contain a cosmetic, fragrance or pharmaceutical product; to contain a product having a cream consistency; or to contain a product sample in a quantity ranging from 1 to 25 ml, preferably between 2 and 15 ml.